A number of common physical, mental and psychological disorders have been associated with states of psychoneuroses or anxiety. Such states typically result in feelings of apprehension, uncertainty or fear, without apparent stimulus or objectively out of proportion to any apparent cause, and may be associated with physiological changes such as tachycardia, sweating and tremors. Furthermore, an extreme state of anxiety is a common consequence of withdrawal from substances capable of inducing drug dependence, such as alcohol, nicotine and cocaine. In use, such substances produce an anxiolytic effect. However, their chronic use is accompanied by a state of dependence. The sudden interruption of these substances may even exacerbate the initial anxiety, making withdrawal from the substances extremely difficult.
The benzodiazepine-type drugs customarily used in the treatment of anxiety have the disadvantage of inducing, on cessation of treatment, an exacerbation of the anxiety and, therefore, do not constitute effective therapy, for instance, for drug addicts undergoing withdrawal. Accordingly, chemical compounds that can relieve states of psychoneuroses or anxiety have been sought for use as pharmaceutical agents in the treatment of patients. In particular, there has been a need for anxiolytic agents that relieve the anxiety of withdrawal from addictive drug substances.
Schizophrenia is an imbalance that encompasses any of a group of severe emotional disorders, usually of psychotic proportions, characterized by misinterpretation and retreat from reality, delusions, hallucinations, ambivalence, inappropriate affect, and withdrawn, bizarre, or regressive behavior. Accordingly, chemical compounds that can relieve the anxiety characteristic of psychotic disorders such as schizophrenia have also been sought for use as pharmaceutical agents in the treatment of patients.
The present theory of the physiopathology of schizophrenia is that an augmented dopaminergic activity in the medial temporal lobes of the brain is responsible for the dopamine induced hyperactivity characteristic of this disorder. Thus, the antipsychotic drugs currently in use are antidopaminergics.